[llvm] [WebAssembly] Split separate component LiveIntervals for TEEs (PR #131561)

[Quentin Colombet via llvm-commits]

qcolombet wrote:

> > > Meanwhile, do you know why this verification rule, which requires a LiveIntervals should not contain unconnected components, exist?
> > 
> > 
> > That's because you don't want to group variables that are otherwise completely unrelated. That creates additional constraints on your allocation for no reason.
> 
> Sorry, not sure if I understand. Then doesn't this effectively ban register coalescing, as I asked in [#131561 (comment)](https://github.com/llvm/llvm-project/pull/131561#issuecomment-2754465095)?

In a way it does, because these two variables are unrelated, so there's no point in coalescing them.
The goal of coalescing is to eliminate copies. Your example has none, so no coalescing is needed.

https://github.com/llvm/llvm-project/pull/131561